The present invention generally relates to a braking assembly and more particularly, to a braking assembly which is deployed within an electric vehicle and which selectively provides vehicular deceleration, effective to provide the occupants of the vehicle with substantially the same xe2x80x9csensexe2x80x9d or xe2x80x9cfeelxe2x80x9d as is provided by the compression braking of an internal combustion engine type of vehicle.
Compression braking of an internal combustion engine typically occurs as the accelerator pedal is released, and is effective to allow the occupants, of the internal combustion type vehicle, to gain a xe2x80x9csensexe2x80x9d or xe2x80x9cfeelxe2x80x9d of deceleration. It is desirable to provide substantially the same xe2x80x9csensexe2x80x9d or xe2x80x9cfeelxe2x80x9d in an electric vehicle and to substantially prevent the vehicle occupants from xe2x80x9csensingxe2x80x9d a coasting type of operation, thereby allowing an electrical vehicle to xe2x80x9cimitatexe2x80x9d well known and desirable attributes of an internal combustion engine type vehicle.
Attempts to provide such compression braking in an electric vehicle typically require the communication of torque or energy from a motor to an electric battery. While these attempts do allow compression braking to occur, they are not reliable since they require the existence of some energy storage capability within the battery and, if the battery is substantially and fully charged, these attempts do not provide the required braking. Moreover, in order for such energy to be effectively communicated, the battery must operatively reside within a certain temperature range and the powertrain must operate below a certain operating temperature. Therefore, these prior attempts provide inconsistent operation.
Further, many electric vehicles do not have electrical batteries. Rather, these xe2x80x9cother typesxe2x80x9d of electric vehicles employ fuel cell assemblies which are not adapted to receive the energy from the motor in the foregoing manner. Such prior attempts are therefore not effective in these fuel cell type vehicles. In order to overcome these drawbacks, other attempts have utilized a relatively complicated and expensive xe2x80x9cbrake by wire systemxe2x80x9d.
There is therefore a need for a braking system which overcomes at least some of the previously delineated drawbacks of prior braking systems and which, by way of example and without limitation, efficiently provides compression braking within an electric vehicle, effective to provide the occupants of the electric vehicle with substantially the same xe2x80x9cfeelxe2x80x9d or xe2x80x9csensexe2x80x9d of deceleration as is provided within an internal combustion engine type vehicle.
It is a first object of the present invention to provide a braking assembly which overcomes at least some of the previously delineated drawbacks of prior braking assemblies.
It is a second object of the present invention to provide a braking assembly which overcomes at least some of the previously delineated drawbacks of prior braking assemblies and which, by way of example and without limitation, provides compression braking within an electric vehicle.
It is a third object of the present invention to provide a method for producing compression braking which is substantially independent of the operating temperature of an electric vehicle, which is substantially independent of the amount of electrical charge contained within a battery, and which is independent of the type of fuel source which is utilized within the vehicle.
According to a first aspect of the present invention a braking assembly is provided. The braking assembly includes a selectively actuated booster which provides negative torque to a wheel in response to a sensed position of an accelerator pedal member.
According to a second aspect of the present invention a method is provided for decelerating an electric vehicle. The method includes the steps of sensing the position of a member; and activating a booster member in response to the sensed position of the member.
These and other features, aspects, and advantages of the present invention will become apparent from a reading of the following detailed description of the preferred embodiment of the invention and by reference to the following drawing.